Rotary fluid device with axially expansible vane

ABSTRACT

A rotary device including a rotor turning in a fluid chamber and containing slots slidably receiving vanes which project into engagement with the walls of the chamber. Each vane includes at least two sections which are relatively axially movable to assure that the assembly occupies the full axial extent of the chamber, with one section having a tongue projecting axially into and slidable within a groove formed in the other section, and with pressure fluid being conducted through a passage which extends through the interior of the latter section and into its groove to urge the sections axially apart.

D United States Patent 1151 3,639,090

Hutchins Feb. 1, 1972 [54] ROTARY FLUID DEVICE WITH 1,290,657 l/l9l9Rasmussen.... ....418/l10 UX AXIALLY EXPANSIBLE VANE 1,737,355 11/1929Bogue 2,189,088 2/1940 Thompson. [72] lnventor: Alma A. Hutchms, 49North Lotus Ave., 72,831,631 4/1953 petal-Sen Pasadenaicahf- 91107 1 12,950,075 I ll/l960 Phillips ..4l8/1|1 [221 1970 I FOREIGN PATENTS ORAPPLICATIONS [21] 26,764 923,027 2/1947 France ..41s/111 RltedU.S.A l t'Dt e a pp a a Primary Examiner Everette A. Powell, Jr. [63] Continuationof Ser. No. 725,019, Apr. 29, 1968, Attorney-William P. Green abandoned.

[57] ABSTRACT 5 .8. Cl.... ..4 P CL A rotary device including a rotorturning in a fluid chamber [58] Field 136 and containing slots slidablyreceiving vanes which project "i' into engagement with the walls of thechamber. Each vane ineludes at least two sections which are relativelyaxially mova- 56] References Cited ble to assure that the assemblyoccupies the full axial extent of the chamber, with one section having atongue projecting axi- UNl ES A S ally into and slidable within a grooveformed in the other section, and with pressure fluid being conductedthrough a 706,158 8/1902 Charles ..4l8/l11 passage which extends throughthe interior f the latter 580 7411617 10/1 903 Bogart tion and into itsgroove to urge the sections axially apart. 776,058 11/1904 Heinze....968,859 8/1910 16 Claims, 6 Drawing Figures Kruger ..418/l11 X ROTARYFLUID DEVICE WITH AXIALLY EXPANSIBLE VANE CROSS-REFERENCE TO RELATEDAPPLICATION This application is a continuation of my copendingapplication, Ser. No. 725,019 filed Apr. 29, 1968, and now abandoned, onRotary Fluid Device With Expansible Vane.

BACKGROUND OF THE INVENTION This invention relates to rotary devices ofa type having a vane, or more usually a series of vanes, coacting with arotor and a stationary body to define a compartment or compartmentswhich vary progressively in size as the rotor turns. Certain of thenovel aspects of the invention may be applied to either a fluid-drivenmotor of the vane type, or a vane-type fluidpump acting to displacefluid in response to turning movement of the rotor. However, theinvention will be described primarily as applied to motors.

One problem which has been encountered in many prior vane-type pumps andmotors has been that of assuring maintenance of an effective fluid sealbetween the varies and the engaged walls of the fluid chamber withinwhich the vanes and rotor turn, and particularly preventing thedevelopment of leakage between the vanes and those walls as a result ofwear and/or inaccuracies in manufacture. To prevent such leakage, someprior devices have included vanes formed of two adjacent plates,constructed to shift axially relative to one another in a manneraltering the overall axial length of the vane in accordance with thelength of the chamber which is to be occupied. However, these priorextensible vane arrangements with which I am familiar have not beencapable of maintaining as effective a seal between the two vanesections, and between the vane sections and the other parts of theapparatus, as would be desired for optimum operational effectiveness,and therefore have not adequately solved the overall leakage problem.

SUMMARY OF THE INVENTION In a device constructed in accordance with thepresent in vention, l utilize an axially extensible vane assemblyincluding twovane sections which are shiftable axially relative to oneanother in essentially the manner set forth above, but in which theconstruction of and relationship between the two vane sections is suchas to assure an improved sealing effectiveness, both between these twosections themselves, and between the vane sections and the adjacentwalls of the fluid chamber. As will appear, to attain these results, Iprovide one of the vane sections with a tongue which projects axiallytoward the other section, and is received slidably within a grooveformed in that section, in a manner forming a very effective slidingessentially fluidtight joint. Preferably, fluid is directed from thehigher pressure side of the vane assembly into the groove, at a locationopposite the tongue of the other section, so that the pressure at thislocation urges the two sections relatively axially apart and toward orinto proper sealing engagement with the chamber walls. The separatingforce exerted in this manner against the two sections is controlled veryeffectively and reliably by conducting the pressure fluid into thegroove through a special passage of fixed dimension which extendsthrough the interior of the section containing the groove, toautomatically attain a spreading force sufficient to attain a properseal and yet light enough to avoid excessive wear of the vane sectionsor engaged parts. Also, fluid from the high-pressure side is for bestresults conducted radially inwardly to the inner side of the vane, toconduct high-pressure fluid to that location in a relationship urgingthe vane radially outwardly to its active position of engagement with anouter wall of the fluid chamber.

BRIEF DESCRIPTION OF THE DRAWING The above and other features andobjects of the invention will be better understood from the followingdetailed description of the typical embodiment illustrated in theaccompany; ing drawing, in which:

FIG. 1 is a side elevational view, partially broken away, ofa fluidmotor constructed in accordance with the invention;

FIG. 2 is a transverse section taken on line 2-2 of FIG. 1; FIG. 3 is agreatly enlarged fragmentary section taken on line 3-3 of FIG. 2;

FIG. 4 is a section taken on line 4-4 of FIG. 3; Fig. 5 is an explodedperspective representation of the two sections of one of the vaneassemblies; and

FIG. 6 is a reduced section taken on line 6-6 of FIG. 4.

DESCRIPTION OF THE PREFERRED EMBODIMENT In FIGS. 1 and 2, I haveillustrated generally at 10 a vanetype rotary device, which maytypically function as either a fluid pump or a fluid motor, but will bedescribed primarily as the latter, having an inlet line 11 through whicha pressurized fluid, such as compressed air, is introduced into the unitto drive its rotor 12 (FIG. 2) rotatively about an axis 13 relative toan outer stationary body or housing 14 of the device, The rotor slidablycarries a series of circularly spaced vane assem blies 15' which areconstructed in accordance with the invention.

The outer stationary body 14 of the device contains an inner cylindricalfluid chamber 16, and may be: formed of an axially extending peripheralwall 17 closed at its opposite ends by two radially extending transverseend walls 18 and 19. More particularly, the peripheral wall 17 of body14 may internally have an axially extending cylindrical inner surface 20centered about an axis 21 which extends parallel to but is offsetlaterally with respect to the previously mentioned. axis 13 of therotor. The two end walls 18 and 19 have planar axially inner surfaces 22and 23, which are disposed transversely of both of the axes l3 and 21,and therefore transversely of the cylindrical internal surface 20 ofperipheral section 17 of the body, to define with surface 20 thecylindrical fluid chamber 16 in the body. Externally, section 17 mayhave an outer cylindrical surface 24 centered about axis 13 of therotor, so that the radial thickness of the wall of section 17 variesprogressively as that wall advances circularly about the axes l3 and 21,as seen in FIG. 2. End walls or plates 18 and 19 may have outercylindrical surfaces 25 also centered about axis 13 and formingcontinuations of surface 24.

The rotor 12 is mounted rigidly to and turns with a typically externallycylindrical shaft 26 which is centered about and turns about axis 13,and whose opposite ends may project axially beyond the end walls orplates 18 and 19 for connection at 27 and/or 28 to a mechanism which isto be driven by the motor. (or is to drive the shaft when the device 10is to function as a pump). The shaft 26 may be mounted for its rotationby suitable ball bearings or other bearings illustrated at 29 and 30,and is keyed to rotor 12 for rotation therewith, as by a key representedat 31 in FIG. 2.

Rotor 12 is of cylindrical configuration, having a radially outercylindrical surface 32 centered about axis 13, but of a diameter lessthan, and eccentric with respect to, the cylindrical surface 20 of fluidchamber 16 in the body. The opposite ends of the rotor are defined bytwo spaced parallel planar oppositely facing end surfaces 33 and 34,disposed transversely of the two axes 13 and 31, and positioned tosubstantially engage the opposite ends 22 and 23 of chamber 16 of thebody. At a series of circularly spaced locations, rotor 12 contains anumber of slots 35 which receive the vane assemblies 15, and lieessentially in planes 36 extending through and containing axis 13. Moreparticularly, each of the slots is defined by two parallel planaropposite sidewall surfaces 37, disposed parallel to and at oppositesides of one of the planes 36, and continuing through the entire axialextent of the rotor, and extending radially inwardly from the peripheralsurface 32 of the rotor to the location of an axially extending innerwall 38 of the slot disposed perpendicular to the sidewall surfaces 37.

IOIDZI As seen best in FIG. 5, each of the vane assemblies includes tworelatively axially shiftable vane sections 39 and 40, which arepreferably formed of a suitable rigid resinous plastic material moldedto the illustrated configuration. Section 39 may be longer axially thansection 40, and has two parallel planar opposite side surfaces 41 and 42(FIG. 4) which are spaced apart a thickness dimension t desirablyslightly less than the width w of the individual slots 35 in the rotor,to occupy approximately the entire width of the slot while leaving onlya small clearance space at 135 to assure free radial movement of thevane section 39 within the rotor slot. These surfaces 41 and 42 extendcontinuously along both sides of the vane except at the location of aradially extending groove or recess 43 formed in one side of the vane ata location interrupting surface 42. At one of its ends, section 39 ofthe vane assembly has a planar end wall surface 44 (FIGS. 3 and 4),which extends directly transversely of axes l3 and 21, and slidablyengages inner end surface 22 of end wall 18 of the outer body of thedevice continuously over the entire extent of end surface 44 and throughthe entire radial extent of the vane. Along its radially outer edge,vane section 39 has an outer planar surface 45 disposed parallel to axis13, and perpendicular to one of the previously mentioned radial planes36 (FIG. 2), and which slidably engages inner cylindrical surface ofsection 17 of the body continuously along the entire axial length ofvane section 39, to form a fluid tight seal at that location. At theradially inner edge of section 39, a similar planar surface 46 may beformed (FIG. 3), extending parallel to outer surface 45 and parallel toaxis 13.

The second section 40 of the vane assembly has a main relatively thickportion 47 and a thinner axially projecting tongue portion 48. The thickportion 47 of section 40 has two opposite side surfaces 49 and 50 whichare planar and parallel to one another and are spaced apart the samethickness dimension t as are the two surfaces 41 and 42 of section 39,and are aligned with and lie in the same planes as those surfaces.Planar end surface 51 of section 40 is disposed parallel to surface 44at the opposite end of section 39, and extends transversely of the twoaxes 13 and 21, and engages transverse end wall surface 23 of the fluidchamber in body 14 continuously over the entire radial extent and theentire thickness of the vane assembly. A radially outer surface 52 ofsection 40 is aligned with and lies in the same plane as outer surface45 of section 39 (FIG. 3), and like surface 45 slidably engages surface20 of the body, to form a seal therewith. A radially inner surface 53 ofsection 40 is aligned with and lies in the same plane as inner surface46 of section 39.

The tongue portion 48 of vane section 40 has a thickness dimension 1which is substantially less than the thickness t of section 39 and thethicker portion 47 of section 40. This tongue is defined at its oppositesides by two spaced parallel planar surfaces 54, which are disposedparallel to but are spaced inwardly from the planes of surfaces 49 and50. Surfaces 54 continue through the entire radial extent of the vaneassembly, from radially outer surface 52 of section 40 to its radiallyinner surface 53, with those surfaces 52 and 53 continuing rightwardlyin FIG. 3 to define the upper and lower ends of the tongue. Therightward extremity of the tongue is defined by a typically planarsurface 55, disposed perpendicular to surfaces 54, and extendingcontinuously from the radially outer surface 52 to the radially innersurface 53 of the vane section 40. Thus, tongue 48 and the remainder ofsection 40 both have a uniform cross section through their entire radialextent. At thejuncture of the tongue and main portion 47 of section 40,the latter may have two narrow surfaces 56 aligned with one another. anddisposed in a plane which is perpendicular to the planes of surfaces 49,50, and 54.

For coaction with tongue 48 of section 40, the section 39 has a radiallyextending groove 57, having a cross section (as viewed in FIG. 4)corresponding substantially to the cross section of tongue 48, toslidably receive that tongue in an interfitting sealing relation. Morespecifically, groove 57 has two opposite sidewall surfaces 58 which areparallel and planar and spaced apart a distance only very slightlygreater than the thickness t of tongue 48, to allow just sufficientclearance with respect to the tongue (desirably about one thousandth ofan inch) to enable relative axial sliding movement of the sections. Atits deepest portion, the groove 57 has an end wall surface 59 which isperpendicular to surfaces 58 and extends radially and parallel to endsurface 55 of the tongue. Opposite surfaces 56 of section 40 of the vaneassembly, section 39 has two aligned planar radially extending surfaces60 disposed parallel to surfaces 56, and perpendicular to surfaces 41and 42.

The recess 43 which is formed in one side of section 39 of the vaneassembly continues through the entire radial extent of section 39, andexcept at the location of an increased depth portion 61 of the recesshas a uniform cross section through that entire radial extent. Thiscross section will be apparent from FIG. 4, where the recess 43 isillustrated as having two spaced parallel opposite sidewall surfaces 62,extending radially, and extending perpendicular to surfaces 41 and 42 ofsection 39, with the inner wall of recess 43 being defined by a radiallyextending surface 63 disposed parallel to surface 42, but spacedinwardly therefrom, and lying in the same plane as one of the groovewalls 58. The increased depth portion 61 of recess 43 takes the form ofan axially extending groove, typically having the rectangular crosssection illustrated in FIG. 6, and communicating with a correspondinglyrectangular and aligned opening or passage 65 extending through thematerial of vane section 39 into the interior of groove 57 (through anopening in the center of inner end surface 59 of the groove).

With reference again to FIG. 2, the inlet line 11 introduces theactuating fluid, desirably compressed air, into the space radiallybetween the rotor and body through a tangential inlet opening 66,locatedjust circularly beyond the point of engagement 67 of theeccentric rotor 12 with the body wall 20. This air acts against thevanes to cause clockwise rotation of the rotor and vanes as viewed inFIG. 2, with the air ultimately discharging from the body or housingthrough an outlet slit 68. As the rotor turns, each of the vaneassemblies 15, including its two sections 39 and 40, progressivelyadvances radially outwardly with respect to the rotor 12, and thenradially inwardly, to continuously slidably engage inner surface 20 ofthe body, and thus divide the chamber within the body into a series ofsuccessive compartments which change progressively in size as the rotorturns. The vanes are maintained against surface 20 by centrifugal forceas the rotor turns. If the vane assemblies are in radially inwardlyretracted positions upon the initial application of pressure throughinlet 11, the pressure will itself act to force the vanes radiallyoutwardly, by virtue of the delivery of some of the pressurized airradially inwardly through passage 43 (which is at the higher pressureside of the vane assembly) to the radially inner side of the assembly,so that the pressure may act radially outwardly against surfaces 46 and53 of FIG. 3, to urge the vane assembly outwardly into sliding contactwith body surface 20.

Some of the high-pressure air from within recess 43 flows through theincreased depth portion 61 of that recess and through passage 65 intothe groove 57 of section 39, to a location opposite the end of tongue48, to thereby exert axial pressure against the tongue in a leftwarddirection as viewed in FIG. 4, and against section 39 in a rightwarddirection as viewed in FIG. 4, so that the two sections 39 and 40 areyieldingly urged axially apart and into tight sliding engagement withend wall surfaces 22 and 23 of the fluid chamber in body 14. Thus, veryeffective sealing engagement of the vane sections with walls of thechamber 16 in the body is assured, to prevent leakage of any of the airpast the vane assembly during operation of the motor. The force withwhich the two vane sections are urged apart is regulated sufficiently bythe fixed restriction afforded by passage 65 to assure against excessivewear which might result from too high a pressure between the sections,while at the same time maintaining a great enough pressure to attain aneffective seal.

nzzo

When the two vane sections 39 and 40 are formed of a resinous plasticmaterial, as is preferred, this material will normally be subject tosome expansion upon subjection to the humidity encountered in thedriving air. The tongue 48 and groove 57 are in this case so dimensionedas to allow for expansion of the tongue to an increased thicknesswithout development of too tight a binding engagement with the groovewalls. Desirably, the tongue and groove have the previously discussedclosely fitting relation in the ultimate expanded condition of theparts, with the tongue still being slidable in the groove in thatcondition, but being at the same time in sufficiently tight engagementwith the groove walls to prevent the leakage of any substantial amountof air past the tongue. The overall thickness of the two sections 39 and40, between surfaces 41 and 42, and surfaces 49 and 50, is also smallenough to assure effective reception of the vane assembly within thecoacting slot 35 in the rotor body after any expansion of the vane whichmay occur due to moisture or the like, and still leaving sufficientclearance space between the vane surfaces and the slot walls 37 to allowfor the desired continual radial movement of the vanes within the slots.For best results, the clearance between vane surfaces 41, 42, 49, and50, and sidewall surfaces 37 of the slots, should be greater (in theexpended or actual operating condition of the parts) than is anyclearance between tongue 48 and the groove walls engaged thereby. In apreferred arrangement, the clearance between the vane sections and slotwalls 37 (the difference between vane thickness dimension r and slotwidth w) is between about 0.003 and 0.005 of an inch, desirably about0.004 of an inch; while the clearance between tongue 48 and groove walls58 is desirably not greater than about 0.002 of an inch, and for bestresults is about 0.001 of an inch.

lclaim:

1. A rotary device comprising a body containing a fluid chamber having aradially outer wall and two opposite end walls, a rotor mounted in saidchamber to turn about a predetermined axis and containing a slot, and avane assembly movably contained in said slot and projecting generallyradially outwardly therefrom into engagement with said outer wall of thechamber and forming a side of a fluid compartment which varies in sizeas the rotor turns, said vane assembly being movable generally radiallyinwardly and outwardly within said slot as the rotor turns and inaccordance with said variation in size of said compartment, said vaneassembly including two sections which are relatively axially shiftableto assure occupancy by said assembly of the entire axial distancebetween said end walls, a first of said vane sections having arelatively thick first portion of a thickness occupying the majorportion of the width of said slot and having a thinner tongue portionprojecting axially from said first portion and of a reduced thicknesssubstantially less than that of said first portion, the second of saidvane sections having a portion adjacent said first section of athickness corresponding substantially to that of said thick firstportion of the first section and occupying the major portion of thewidth of the slot, said portion of the second section containing anaxially facing essentially radially extending groove slidably receivingsaid tongue in relatively axially expansible relation, said portion ofthe second section forming two spaced projections defining said grooveand extending essentially along opposite sides of the groove and alongopposite sides of the tongue to slidably confine it therebetween, therebeing a fluid passage extending within the interior of said secondsection and having an end leading into said groove through an opening ina wall of the groove and conducting fluid from a pressure side of thevane assembly through the interior of said second section to a locationwithin said groove and axially between the sections to yieldingly urgethem axially apart.

2. A rotary device as recited in claim 1, in which one of said sectionsis recessed at its pressure side in a relation to conduct pressure fluidto the radially inner side of said assembly to a location at which iturges the assembly radially outwardly.

3. A rotary device comprising a body containing a fluid chamber having aradially outer wall and two opposite end walls, a rotor mounted in saidchamber to turn about a predetermined axis and containing a slot, and avane assembly movably contained in said slot and projecting generallyradially outwardly therefrom into engagement with said outer wall of thechamber and forming a side of a fluid compartment which varies in sizeas the rotor turns, said vane assembly being movable generally radiallyinwardly and outwardly within said slot as the rotor turns and inaccordance with said variation in size of said compartment, said vaneassembly including two sections which are relatively axially shiftableto assure occupancy by said assembly of the entire axial distancebetween said end walls, a first of said vane sections having arelatively thick first portion of a thickness occupying the majorportion of the width of said slot and having a thinner tongue portionprojecting axially from said first portion and of a reduced thicknesssubstantially less than that of said first portion, the second of saidvane sections having a portion adjacent said first section of athickness corresponding substantially to that of said thick firstportion of the first section and occupying the major portion of thewidth of the slot, said portion of the second section containing anaxially facing essen tially radially extending groove slidably receivingsaid tongue in relatively axially expansible relation, said portion ofthe second section forming two spaced projections defining said grooveand extending essentially radially along opposite sides of the grooveand along opposite sides of the tongue to slidably confine ittherebetween, said second section containing a recess formed in apressure side thereof into which pressure fluid can flow from saidpressure side, there being a fluid passage extending within the interiorof said second section, with the material of said second sectionextending entirely about and defining said passage, and with saidpassage having a first end opening into said recess and a second endopening into said groove for conducting fluid from the pressure side ofthe vane assembly through the interior of said second section to alocation within said groove and axially between the sections toyieldingly urge them axially apart.

4-. A rotary device as recited in claim 3, in which said second end ofsaid passage opens into the groove through an opening formed in an innerwall of the groove and entirely surrounded by the material of saidsecond section axially opposite said tongue.

5. A rotary device as recited in claim 3, in which said recess has aportion of increased depth formed. in said pressure side of said secondsection and extending into the material of said second section fartherthan the remainder of the recess, said first end of said passage beingpositioned to open into said increased depth portion of the recess andreceive fluid therefrom.

6. A rotary device as recited in claim El, in which said recesscontinues generally radially inwardly to a location at which it passespressure fluid from said recess to the radially inner side of saidassembly in a relation urging the assembly radially outwardly.

7. A rotary device as recited in claim 3, in which said recess has aportion of increased depth formed in said pressure side of said secondsection and extending into the material of said second section fartherthan the remaindler of the recess, said first end of said passage beingpositioned to open into said increased depth portion of the recess andreceive fluid therefrom, said second end of the passage opening into thegroove through an opening formed in an inner wall of the groove axiallyopposite said tongue.

8. A rotary device as recited in claim 3, in which said recess extendsgenerally radially in the pressure side of said second section andcontinues from the radially outer extremity of the vane to its radiallyinner extremity and acts to pass pressure fluid to the radially innerside of said vane assembly to urge it radially outwardly, said recessbeing located axially beyond said groove in a direction away from saidfirst section, said recess having an axially extending portion ofincreased depth formed in said pressure side of the second section andextending into the material of said second section farther than otherportions of the recess both radially inwardly and radially outwardlythereof, said passage forming a continuation of said increased depthportion of the recess and extending axially therefrom into the groovethrough the interior of the second section and through an inner wall ofthe groove axially opposite said tongue.

9. A vane assembly to be mounted movably within a slot in a rotor of arotary device, including two sections which are relatively axiallyshiftable, a first of said vane sections having a relatively thick firstportion ofa thickness to occupy the major portion of the width of saidslot and having a thinner tongue portion projecting axially from saidfirst portion and of a reduced thickness substantially less than that ofsaid first portion, the second of said vane sections having a portionadjacent said first section of a thickness corresponding substantiallyto that of said thick first portion of the first section to occupy themajor portion of the width of the slot, said portion of the secondsection containing an axially facing essentially radially extendinggroove slidably receiving said tongue in relatively axially expansiblerelation, said portion of the second section forming two spacedprojections defining said groove and extending essentially radiallyalong opposite sides of the groove and along opposite sides of thetongue to slidably confine it therebetween, there being a fluid passageextending within the interior of said second section and conductingfluid from a pressure side thereof through the interior of said secondsection to a location within said groove and axially between thesections to yieldingly urge them axially apart.

10. A vane assembly as recited in claim 9, in which said second sectioncontains a recess formed in said pressure side thereof and leadingpressure fluid from said pressure side into said passage for deliverytherethrough into said groove.

IL A vane assembly as recited in claim 9, in which one of said sectionsis recessed at said pressure side in a relation to conduct pressurefluid to the radially inner side of said assembly and thereby urge itradially outwardly.

12. A vane assembly as recited in claim 9, in which said passage opensinto said groove through an opening formed in an inner wall of thegroove axially opposite said tongue.

13. A vane assembly as recited in claim 9, in which said second sectioncontains a recess formed in said pressure side thereof and leadingpressure fluid from said pressure side into said passage for deliverytherethrough into said said groove, said recess having a portion ofincreased depth formed in said pressure side of said second section andextending into the material of said second section farther than theremainder of the recess and into which said passage opens.

14. A vane assembly as recited in claim 9, in which said recesscontinues generally radially inwardly to a location at which it passespressure fluid from said recess to the radially inner side of saidassembly in a relation urging the assembly radially outwardly.

15. A vane assembly as recited in claim 9, in which said second sectioncontains a recess formed in said pressure side thereof and leadingpressure fluid from said pressure side into said passage for deliverytherethrough into said groove, said recess having a portion of increaseddepth formed in said pressure side of said second section and extendinginto the material of said second section farther than the remainder ofthe recess and into which said passage opens, said passage opening intosaid groove through an opening formed in an inner wall of the grooveaxially opposite said tongue.

16. A vane assembly as recited in claim 9, in which said second sectioncontains a recess formed in said pressure side thereof and leadingpressure fluid from said pressure side into said passage for deliverytherethrough into said groove, said recess extending generally radiallyin the pressure side of said second section and continuing from theradially outer extremity of the vane to its radially inner extremity andacting to pass pressure fluid to the radially inner side of saidassembly to urge it radially outwardclg, said groove being locatedaxially beyond said groove in a irectlon away from said first section,

said recess having an axially extending portion of increased depthformed in said pressure side of the second section and extending intothe material of said second section farther than other portions of therecess both radially inwardly and radially outwardly thereof, saidpassage forming a continuation of said increased depth portion of therecess and extending axially therefrom into the groove through theinterior of the second section and through an inner wall of the grooveaxially 0pposite said tongue.

1. A rotary device comprising a body containing a fluid chamber having aradially outer wall and two opposite end walls, a rotor mounted in saidchamber to turn about a predetermined axis and containing a slot, and avane assembly movably contained in said slot and projecting generallyradially outwardly therefrom into engagement with said outer wall of thechamber and forming a side of a fluid compartment which varies in sizeas the rotor turns, said vane assembly being movable generally radiallyinwardly and outwardly within said slot as the rotor turns and inaccordance with said variation in size of said compartment, said vaneassembly including two sections which are relatively axially shiftableto assure occupancy by said assembly of the entire axial distancebetween said end walls, a first of said vane sections having arelatively thick first portion of a thickness occupying the majorportion of the width of said slot and having a thinner tongue portionprojecting axially from said first portion and of a reduced thicknesssubstantially less than that of said first portion, the second of saidvane sections having a portion adjacent said first section of athickness corresponding substantially to that of said thick firstportion of the first section and occupying the major portion of thewidth of the slot, said portion of the second section containing anaxially facing essentially radially extending groove slidably receivingsaid tongue in relatively axially expansible relation, said portion ofthe second section forming two spaced projections defining said grooveand extending essentially along opposite sides of the groove and alongopposite sides of the tongue to slidably confine it therebetween, therebeing a fluid passage extending within the interior of said secondsection and having an end leading into said groove through an opening ina wall of the groove and conducting fluid from a pressure side of thevane assembly through the interior of said second section to a locationwithin said groove and axially between the sections to yieldingly urgethem axially apart.
 2. A rotary device as recited in claim 1, in whichone of said sections is recessed at its pressure side in a relation toconduct pressure fluid to the radially inner side of said assembly to alocation at which it urges the assembly radially outwardly.
 3. A rotarydevice comprising a body containing a fluid chamber having a radiallyouter wall and two opposite end walls, a rotor mounted in said chamberto turn about a predetermined axis and containing a slot, and a vaneassembly movably contained in said slot and projecting generallyradially outwardly therefrom into engagement with said outer wall of thechamber and forming a side of a fluid compartment which varies in sizeas the rotor turns, said vane assembly being movable generally radiallyinwardly and outwardly within said slot as the rotor turns and inaccordance with said variation in size of said compartment, said vaneassembly including two sections which are relatively axially shiftableto assure occupancy by said assembly of the entire axial distancebetween said end walls, a first of said vane sections having arelatively thick first portion of a thickness occupying the majorportion of the width of said slot and having a thinner tongue portionprojecting axially from said first portion and of a reduced thicknesssubstantially less than that of said first portion, the second of saidvane sections having a portion adjacent said first section of athickness corresponding substantially to that of said thick firstportion of the first section and occupying the major portion of thewidth of the slot, said portion of the second section containing anaxially facing essentially radially extending groove slidably receivingsaid tongue in relatively axially expansible relation, said portion ofthe second section forming two spaced projections defining said Grooveand extending essentially radially along opposite sides of the grooveand along opposite sides of the tongue to slidably confine ittherebetween, said second section containing a recess formed in apressure side thereof into which pressure fluid can flow from saidpressure side, there being a fluid passage extending within the interiorof said second section, with the material of said second sectionextending entirely about and defining said passage, and with saidpassage having a first end opening into said recess and a second endopening into said groove for conducting fluid from the pressure side ofthe vane assembly through the interior of said second section to alocation within said groove and axially between the sections toyieldingly urge them axially apart.
 4. A rotary device as recited inclaim 3, in which said second end of said passage opens into the groovethrough an opening formed in an inner wall of the groove and entirelysurrounded by the material of said second section axially opposite saidtongue.
 5. A rotary device as recited in claim 3, in which said recesshas a portion of increased depth formed in said pressure side of saidsecond section and extending into the material of said second sectionfarther than the remainder of the recess, said first end of said passagebeing positioned to open into said increased depth portion of the recessand receive fluid therefrom.
 6. A rotary device as recited in claim 3,in which said recess continues generally radially inwardly to a locationat which it passes pressure fluid from said recess to the radially innerside of said assembly in a relation urging the assembly radiallyoutwardly.
 7. A rotary device as recited in claim 3, in which saidrecess has a portion of increased depth formed in said pressure side ofsaid second section and extending into the material of said secondsection farther than the remainder of the recess, said first end of saidpassage being positioned to open into said increased depth portion ofthe recess and receive fluid therefrom, said second end of the passageopening into the groove through an opening formed in an inner wall ofthe groove axially opposite said tongue.
 8. A rotary device as recitedin claim 3, in which said recess extends generally radially in thepressure side of said second section and continues from the radiallyouter extremity of the vane to its radially inner extremity and acts topass pressure fluid to the radially inner side of said vane assembly tourge it radially outwardly, said recess being located axially beyondsaid groove in a direction away from said first section, said recesshaving an axially extending portion of increased depth formed in saidpressure side of the second section and extending into the material ofsaid second section farther than other portions of the recess bothradially inwardly and radially outwardly thereof, said passage forming acontinuation of said increased depth portion of the recess and extendingaxially therefrom into the groove through the interior of the secondsection and through an inner wall of the groove axially opposite saidtongue.
 9. A vane assembly to be mounted movably within a slot in arotor of a rotary device, including two sections which are relativelyaxially shiftable, a first of said vane sections having a relativelythick first portion of a thickness to occupy the major portion of thewidth of said slot and having a thinner tongue portion projectingaxially from said first portion and of a reduced thickness substantiallyless than that of said first portion, the second of said vane sectionshaving a portion adjacent said first section of a thicknesscorresponding substantially to that of said thick first portion of thefirst section to occupy the major portion of the width of the slot, saidportion of the second section containing an axially facing essentiallyradially extending groove slidably receiving said tongue in relativelyaxially expansible relation, said portion of the second section formingtwo spaced projections defining said groove and extending essentiallyradially along opposite sides of the groove and along opposite sides ofthe tongue to slidably confine it therebetween, there being a fluidpassage extending within the interior of said second section andconducting fluid from a pressure side thereof through the interior ofsaid second section to a location within said groove and axially betweenthe sections to yieldingly urge them axially apart.
 10. A vane assemblyas recited in claim 9, in which said second section contains a recessformed in said pressure side thereof and leading pressure fluid fromsaid pressure side into said passage for delivery therethrough into saidgroove.
 11. A vane assembly as recited in claim 9, in which one of saidsections is recessed at said pressure side in a relation to conductpressure fluid to the radially inner side of said assembly and therebyurge it radially outwardly.
 12. A vane assembly as recited in claim 9,in which said passage opens into said groove through an opening formedin an inner wall of the groove axially opposite said tongue.
 13. A vaneassembly as recited in claim 9, in which said second section contains arecess formed in said pressure side thereof and leading pressure fluidfrom said pressure side into said passage for delivery therethrough intosaid said groove, said recess having a portion of increased depth formedin said pressure side of said second section and extending into thematerial of said second section farther than the remainder of the recessand into which said passage opens.
 14. A vane assembly as recited inclaim 9, in which said recess continues generally radially inwardly to alocation at which it passes pressure fluid from said recess to theradially inner side of said assembly in a relation urging the assemblyradially outwardly.
 15. A vane assembly as recited in claim 9, in whichsaid second section contains a recess formed in said pressure sidethereof and leading pressure fluid from said pressure side into saidpassage for delivery therethrough into said groove, said recess having aportion of increased depth formed in said pressure side of said secondsection and extending into the material of said second section fartherthan the remainder of the recess and into which said passage opens, saidpassage opening into said groove through an opening formed in an innerwall of the groove axially opposite said tongue.
 16. A vane assembly asrecited in claim 9, in which said second section contains a recessformed in said pressure side thereof and leading pressure fluid fromsaid pressure side into said passage for delivery therethrough into saidgroove, said recess extending generally radially in the pressure side ofsaid second section and continuing from the radially outer extremity ofthe vane to its radially inner extremity and acting to pass pressurefluid to the radially inner side of said assembly to urge it radiallyoutwardly, said groove being located axially beyond said groove in adirection away from said first section, said recess having an axiallyextending portion of increased depth formed in said pressure side of thesecond section and extending into the material of said second sectionfarther than other portions of the recess both radially inwardly andradially outwardly thereof, said passage forming a continuation of saidincreased depth portion of the recess and extending axially therefrominto the groove through the interior of the second section and throughan inner wall of the groove axially opposite said tongue.